Facebook terminated an anonymous, pro-Trump online group created by employees in December 2016, according to a Business Insider report published Wednesday.

CEO and co-founder Mark Zuckerberg reportedly justified the decision by alleging the forum helped spread harassment.

Known as Facebook Anon, the internal group was created in May 2015 and lasted until December 2016 when company leadership shut it down. A sign with the beginning and end dates of the group as well as the pithy phrase “Silenced, but not silent” appeared on Facebook’s campus after the tech conglomerate issued the kibosh.

The tipping point for Facebook may have been when it heard there were debates over the Black Lives Matter movement in the forum, as that coalition and cause was further emerging in early 2016, Business Insider reports. Around that same time, Zuckerberg scolded workers who crossed out the activist groups’ name with “All Lives Matter” on the company’s signature wall.